Patients with gyrate atrophy of the retina are examined systematically to confirm the diagnosis. Skin fibroblasts grown in tissue culture are assayed for ornithine aminotransferase activity. Other enzymatic activities related to ornithine metabolism such as ornithine decarboxylase activity will be measured. The results will be examined for correlation with the presence of homo- or heterozygosity for the disease trait. Patients will be given pyridoxine to see if the serum concentration of ornithine can be reduced, and if so, the patient will be classified as a "responder," and treatment with pyridoxine will be continued. Nonresponder and responder patients will be planced on a low arginine, low protein diet with supplemental amino acids and observed for an arrest of improvement of their disease.